2 * linux/arch/arm/mach-integrator/cpu.c
4 * Copyright (C) 2001-2002 Deep Blue Solutions Ltd.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
10 * CPU support functions
12 #include <linux/module.h>
13 #include <linux/types.h>
14 #include <linux/kernel.h>
15 #include <linux/cpufreq.h>
16 #include <linux/slab.h>
17 #include <linux/sched.h>
18 #include <linux/smp.h>
19 #include <linux/init.h>
22 #include <mach/hardware.h>
23 #include <mach/platform.h>
24 #include <asm/mach-types.h>
25 #include <asm/hardware/icst525.h>
27 static struct cpufreq_driver integrator_driver
;
29 #define CM_ID IO_ADDRESS(INTEGRATOR_HDR_ID)
30 #define CM_OSC IO_ADDRESS(INTEGRATOR_HDR_OSC)
31 #define CM_STAT IO_ADDRESS(INTEGRATOR_HDR_STAT)
32 #define CM_LOCK IO_ADDRESS(INTEGRATOR_HDR_LOCK)
34 static const struct icst_params lclk_params
= {
36 .vco_max
= ICST525_VCO_MAX_5V
,
43 static const struct icst_params cclk_params
= {
45 .vco_max
= ICST525_VCO_MAX_5V
,
53 * Validate the speed policy.
55 static int integrator_verify_policy(struct cpufreq_policy
*policy
)
59 cpufreq_verify_within_limits(policy
,
60 policy
->cpuinfo
.min_freq
,
61 policy
->cpuinfo
.max_freq
);
63 vco
= icst525_hz_to_vco(&cclk_params
, policy
->max
* 1000);
64 policy
->max
= icst525_hz(&cclk_params
, vco
) / 1000;
66 vco
= icst525_hz_to_vco(&cclk_params
, policy
->min
* 1000);
67 policy
->min
= icst525_hz(&cclk_params
, vco
) / 1000;
69 cpufreq_verify_within_limits(policy
,
70 policy
->cpuinfo
.min_freq
,
71 policy
->cpuinfo
.max_freq
);
77 static int integrator_set_target(struct cpufreq_policy
*policy
,
78 unsigned int target_freq
,
79 unsigned int relation
)
81 cpumask_t cpus_allowed
;
82 int cpu
= policy
->cpu
;
84 struct cpufreq_freqs freqs
;
88 * Save this threads cpus_allowed mask.
90 cpus_allowed
= current
->cpus_allowed
;
93 * Bind to the specified CPU. When this call returns,
94 * we should be running on the right CPU.
96 set_cpus_allowed(current
, cpumask_of_cpu(cpu
));
97 BUG_ON(cpu
!= smp_processor_id());
99 /* get current setting */
100 cm_osc
= __raw_readl(CM_OSC
);
102 if (machine_is_integrator()) {
103 vco
.s
= (cm_osc
>> 8) & 7;
104 } else if (machine_is_cintegrator()) {
107 vco
.v
= cm_osc
& 255;
109 freqs
.old
= icst525_hz(&cclk_params
, vco
) / 1000;
111 /* icst525_hz_to_vco rounds down -- so we need the next
112 * larger freq in case of CPUFREQ_RELATION_L.
114 if (relation
== CPUFREQ_RELATION_L
)
116 if (target_freq
> policy
->max
)
117 target_freq
= policy
->max
;
118 vco
= icst525_hz_to_vco(&cclk_params
, target_freq
* 1000);
119 freqs
.new = icst525_hz(&cclk_params
, vco
) / 1000;
121 freqs
.cpu
= policy
->cpu
;
123 if (freqs
.old
== freqs
.new) {
124 set_cpus_allowed(current
, cpus_allowed
);
128 cpufreq_notify_transition(&freqs
, CPUFREQ_PRECHANGE
);
130 cm_osc
= __raw_readl(CM_OSC
);
132 if (machine_is_integrator()) {
133 cm_osc
&= 0xfffff800;
134 cm_osc
|= vco
.s
<< 8;
135 } else if (machine_is_cintegrator()) {
136 cm_osc
&= 0xffffff00;
140 __raw_writel(0xa05f, CM_LOCK
);
141 __raw_writel(cm_osc
, CM_OSC
);
142 __raw_writel(0, CM_LOCK
);
145 * Restore the CPUs allowed mask.
147 set_cpus_allowed(current
, cpus_allowed
);
149 cpufreq_notify_transition(&freqs
, CPUFREQ_POSTCHANGE
);
154 static unsigned int integrator_get(unsigned int cpu
)
156 cpumask_t cpus_allowed
;
157 unsigned int current_freq
;
161 cpus_allowed
= current
->cpus_allowed
;
163 set_cpus_allowed(current
, cpumask_of_cpu(cpu
));
164 BUG_ON(cpu
!= smp_processor_id());
166 /* detect memory etc. */
167 cm_osc
= __raw_readl(CM_OSC
);
169 if (machine_is_integrator()) {
170 vco
.s
= (cm_osc
>> 8) & 7;
171 } else if (machine_is_cintegrator()) {
174 vco
.v
= cm_osc
& 255;
177 current_freq
= icst525_hz(&cclk_params
, vco
) / 1000; /* current freq */
179 set_cpus_allowed(current
, cpus_allowed
);
184 static int integrator_cpufreq_init(struct cpufreq_policy
*policy
)
187 /* set default policy and cpuinfo */
188 policy
->cpuinfo
.max_freq
= 160000;
189 policy
->cpuinfo
.min_freq
= 12000;
190 policy
->cpuinfo
.transition_latency
= 1000000; /* 1 ms, assumed */
191 policy
->cur
= policy
->min
= policy
->max
= integrator_get(policy
->cpu
);
196 static struct cpufreq_driver integrator_driver
= {
197 .verify
= integrator_verify_policy
,
198 .target
= integrator_set_target
,
199 .get
= integrator_get
,
200 .init
= integrator_cpufreq_init
,
201 .name
= "integrator",
204 static int __init
integrator_cpu_init(void)
206 return cpufreq_register_driver(&integrator_driver
);
209 static void __exit
integrator_cpu_exit(void)
211 cpufreq_unregister_driver(&integrator_driver
);
214 MODULE_AUTHOR ("Russell M. King");
215 MODULE_DESCRIPTION ("cpufreq driver for ARM Integrator CPUs");
216 MODULE_LICENSE ("GPL");
218 module_init(integrator_cpu_init
);
219 module_exit(integrator_cpu_exit
);